About 70 million Americans suffer from a sleep problem; nearly 60 percent of them have a chronic disorder. The quantity of sleep that a person gets is not as important as quality. Sleep is primarily a restorative process that influences the homeostatic regulation of the autonomic, neuroendocrine, and immune systems. The behavioral habits, sleep related breathing disorders such as apnea, drugs such as sleeping pills and alcoholic beverages can suppress certain stages of sleep leading to poor sleep quality or even sleep deprivation that have serious effects on individual's health and wellness and lead to various medical problems like cognitive impairment and heart.
Obstructive Sleep Apnea (OSA) is a common disorder that affects about 4% of the general population. People with sleep apnea literally stop breathing repeatedly during their sleep, often for a period of 10-30 seconds and as many as hundreds of times during one night. The frequent arousals and the inability to achieve or maintain the deeper stages of sleep can lead to excessive daytime sleepiness, non-restorative sleep, automobile accidents, personality changes, decreased memory, erectile dysfunction (impotence), and depression. OSA has also been linked to angina, nocturnal cardiac arrhythmias, myocardial infarction and stroke.
There are several currently existing solutions for diagnosing OSA. The primary method for diagnosing OSA currently is to have the patient undergo a sleep study, known as Polysomnography (PSG). A polysomnogram typically records a minimum of eleven channels of various bio-signals requiring a minimum of 22 wire attachments to the patient in a specialized sleep laboratory with attended personnel. Obstructive sleep apnea is diagnosed if the patient has an apnea index (apneic episodes per hour) of greater than 5. Polysomnography is a very costly procedure and does not lend itself to application outside of a medical facility.
Specialized devices using SpO2 oximetry sensors that detect apnea intervals have also been used. These systems have proprietary SpO2 wired sensors and the detected intervals tend to combine multiple apnea episodes. Thus, individual apnea episodes are not detectable using SpO2 oximetry sensors.
Other devices include commercial sleep monitors using brain waves (EEG), ECG and proprietary devices and protocols, which do not satisfactorily detect apneic episodes.